Based on the name, it suggests that it is a curl-defining milk or lotion. This type of product is commonly used to enhance and define natural curls or waves in the hair. curl-defining milk or lotion typically contains moisturizing and styling ingredients that help to define and enhance the natural curl pattern. These products can provide moisture, reduce frizz, and promote more defined and bouncy curls or waves. To use a curl-defining milk or lotion like Laura Sims Lait Définition Boucles, it is generally applied to damp or wet hair. The product is usually distributed evenly throughout the hair, focusing on the mid-lengths and ends. It can be further worked into the hair using fingers or a wide-toothed comb to encourage curl formation. After applying the product, the hair can be air-dried or diffused for best results.